This invention relates to office machines. More particularly, the present invention relates to an ink regulation system for the printer of an office machine.
One such office machine is an electrophotographic printing apparatus. In apparatus of this type commonly used today, a photoconductive insulating member is typically charged to a uniform potential and thereafter exposed to a light image of an original document to be reproduced. The exposure discharges the photoconductive insulating surface in exposed or background areas and creates an electrostatic latent image on the member which corresponds to the image contained within the original document. Alternatively, a light beam may be modulated and used to selectively discharge portions of the charged photoconductive surface to record the desired information thereon. Typically, such a system employs a laser beam. Subsequently, the electrostatic latent image on the photoconductive insulating surface is made visible by developing the image with developer powder referred to in the art as "toner." Most development systems employ developer which comprises both charged carrier particles and charged toner particles which triboelectrically adhere to the carrier particles. During development, the toner particles are attracted from the carrier particles by the charged pattern of the image areas of the photoconductive insulating area to form a powder image on the photoconductive area. This toner image may be subsequently transferred to a support surface, such as a sheet of copy paper to which it may be permanently affixed by heating or by the application of pressure.
In commercial applications of such products, the photoconductive member has typically been configured in the form of a belt or drum moving at high speed in order to provide high speed multiple copying from an original document.
It is known to have a reproduction machine such as an electrophotographic copier with a main copying station for copying a set of documents. After the documents are copied, they are bound. A document finishing section of such a machine can include a printing station for printing on the binding of a book. The printing station can print on a binder tape before the book is bound, or the printer can print directly on the binding after the book is bound. Either ink jet printers or impact type printers can be utilized. Such an apparatus is disclosed in U.S. Pat. No. 5,174,556. Although this known apparatus prints on the binding of a book, it does not enable printing directly on each sheet of paper as it emerges from the printer station of the electrophotographic copier.
However, it is now considered desirable to provide a machine operator the option of producing a printed sheet which has on it not only the information from a primary printer, but also an auxiliary printed indicium produced by an auxiliary printer which is selectively employed.
It would also be advantageous to allow the auxiliary printer to be readily detached from the office machine for replacement or maintenance as desired. Moreover, it would be advantageous to allow the user of the office machine to custom mix a desired color of ink for the auxiliary printer, or to use different colors of ink for different printing jobs.
Ink jet printing units are by now well known. An ink jet printer which is encased in a printer head unit that is detachably mounted on a carriage is also known. Such a unit is disclosed in U.S. Pat. No. 4,800,398. However, this unit does not have an on board and readily detachable ink container to allow the operator to custom mix ink for custom color or to use premixed custom colors. In addition, neither this unit nor the other known ink jet printers are capable of handling large volumes of ink rapidly.
Accordingly, it has been considered desirable to develop a new and improved printer ink regulation system which would overcome the foregoing difficulties and others while providing better and more advantageous overall results.